Twitter has just signed a long-term lease on a new location in a blighted area of San Francisco, the company has confirmed.

Earlier this year, the city government voted to give Twitter a temporary tax break -- basically, it won't tax Twitter on the value of employee stock options for the next five years, potentially saving the company millions of dollars when it goes public. But the deal was only valid if Twitter moved to a particular part of San Francisco near the Civic Center and Tenderloin -- two downtown neighborhoods with high vacancy rates. The idea was that Twitter would spur a wave of revitalization in the area.

The city controller pointed out that Twitter could still save money by moving to a suburb, and recommended the tax break as a bare minimum, but apparently the lure of staying in SF was too much to turn down.